Normally, the solar panel converts solar energy during the day time into electrical power to charge up or to maintain a charge in a battery power pack which supplies the lamp during the night as required.
Customarily, the panel is oriented to be directly facing the sun, that is, with its planar surface at least approximately perpendicular to the direction of the sun at noon each day. The conversion of solar energy by a solar panel is most efficient in this position but as the sun moves throughout the daylight hours, the panel is for most of the day operating at considerably less than its optimum efficiency.